Severe Undernutrition Predicts Adverse Outcomes in Transplant Norovirus Infection

Norovirus infection is a frequent cause of diarrhea after kidney transplantation, with heterogeneous clinical presentations. Without specific antiviral treatment, management mainly relies on minimization of immunosuppression. However, prognostic factors for mortality and graft loss remain poorly defined.

We performed a multicenter retrospective study of kidney transplant recipients (KTRs) with norovirus infection between January 2017 and December 2022. A multicentric matched control group of 96 KTRs with nonnorovirus diarrhea was included for comparative nutritional analysis. Variables were collected at baseline, diagnosis, and follow-up, and included recipient or donor characteristics, infection features, immunosuppressive adjustment, nutritional status, and outcomes. Factors associated with mortality and graft loss were analyzed using univariate and multivariate models.

A total of 159 KTRs with norovirus infection were followed-up for a median of 2.7 years. At diagnosis, the norovirus group showed a significantly greater decrease in body mass index (BMI) than the controls (-5.5% vs. -1.5%, P < 0.0001), along with a higher prevalence of severe undernutrition (29.6% vs. 10.4%, P = 0.0010). Mortality (7.3 events/100 person-years) and graft loss (4.4 events/100 person-years) increased stepwise with the severity of undernutrition. Severe undernutrition at diagnosis was independently associated with both mortality (hazard ratio [HR] = 3.87 [1.34-11.21], P = 0.0126) and graft loss (HR = 2.96 [1.02-8.60], P = 0.0468), along with age, diabetes, and baseline creatininemia. Despite immunosuppressive minimization, no significant improvement in survival outcomes was observed.

Severe undernutrition at diagnosis is a major independent predictor of adverse outcomes in KTRs with norovirus infection. Therefore, we recommend close monitoring of nutritional parameters and active nutrition strategies to prevent severe undernutrition in this high-risk population.